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59 LANDTECHNIK 3/2004Hagen Bauersachs and Joachim Meyer, Freising
Life Cycle Inventory Analysis in Horticulture
A conceptual framework for an environmental information management system
A
broad variety of different methods and instruments for environmental assess- ment is currently available. Besides the Life Cycle Assessment (LCA; [5]) there are me- thods like Environmental Performance Eva- luation (EPE; [2, 6]), Ecological Book- keeping [8] or Streamlined LCA [4] to name only a few. A common part of most of these methods is an information basis composed of comprehensive data on material and ener- gy input, usage and output regarding the pro- duct or production system to be investigated.As collection and processing of data on ma- terial and energy flows is a resource inten- sive task, appropriate software tools could be used to assist in this part of environmental information management. The design and development of such a software tool for in- formation management in horticultural pro- duction systems is the aim of the project
“Environmental management in Horticultu- re” of the Technische Universität München.
Requirements of an environmental information management tool for horticulture
General requirements of an ideal environ- mental information system on the business- level can be summarised as follows [3, 7]:
• Data comprehensiveness: all relevant envi- ronmental aspects of the production system should be covered.
• Data aggregation: the vast amount of accu- mulated raw data has to be condensed to meaningful information
• Data relevance currency: data have to be collected and processed timely to allow timely integration of environmental infor- mation in operational and strategic mana- gement decisions
• Data traceability: the methods of data collection, aggregation and assessment have to be traceable.
For the practical usability of an environ-
Agricultural and horticultural pro- ducers have been forced to include environmental aspects in their bu- siness strategies in recent years.
This pressure, not only originating from consumers, but especially from the food industry, retailers and government authorities, ex- presses itself in an increased de- mand for information about “eco- logical quality” in agricultural and horticultural products. Here a computer-aided tool is presented, which should make it possible to collect and assess this information in a horticultural enterprise.
Dipl.-Ing. agr. (Univ.) Hagen Bauersachs is a scientist of the department Horticultural Engineer- ing (Head: Prof. Dr. Joachim Meyer) of the Techni- cal University München, Am Staudengarten 2, D- 85354 Freising-Weihenstephan;
e-mail: hagen.bauersachs@wzw.tum.de This project is sponsored by the BMVEL.
Keywords
Life cycle assessment (LCA), business’ environ- mental information systems
Literature
Literature references can be called up under LT 04328 via internet http://www.landwirtschaftsver- lag.com/landtech/local/literatur.htm.
Fig. 1: Graphical presentation of the data model of a horticultural enterprise as a data tree (left) and as a graph (right)
mental information management tool in hor- ticultural production, two further more spe- cific requirements are important:
• Acquisition of specific material and ener- gy flows: other than in most industrial pro- duction systems, there are different materi- al and energy flows in outdoor horticultural production systems, that can hardly be mo- nitored through measurement, e.g. evapo- transpiration, soil water leakage or nitro- gen uptake by plants. These flows are dependent on highly dynamic and/or site- specific parameters like climate data, soil properties, crop properties etc. Alternative- ly such values like evapotranspiration have to be estimated using appropriate models.
• Economic efficiency: as mentioned above the comprehensive collection and process- ing of relevant environmental data is a very resource intensive task. Therefore it is im- portant that the financial input related to the implementation and maintenance of an information management system does not exceed its attainable financial benefits.
Conceptual framework and implementation
A fundamental task in developing a tool for information management concerns the re- presentation and management of real-world information as abstract entities that can be handled by the computer. For this modelling purpose an object-oriented design approach was selected. In object-oriented programm- ing so called “objects” are used as represen- tations of real-life entities. Objects - as their corresponding real-life entities - share two
characteristics: each object has a state and a behaviour. The representation of a real-world system in this modelling approach can be viewed as a population of interacting ob- jects, each of which is an atomic bundle of data and functionality [9].
The aim of the conceptual framework of the information management system is the analysis of single horticultural companies.
Therefore the main object type used in the model represents one company. Each single company object consists of an arbitrary com- bination of sub-objects. These sub-objects are classified to the following object types:
• Area objects: represent the fields that are available for crop cultivation within the company
• Crop objects: represent a plant spe- cies cultivated on a specific area ob- ject at a specific date
• Device objects: basically represent machine objects like tractors, tillage machinery, irrigation equipment etc.
• Process objects: an abstract object ty- pe defining the usage of one or more device objects on a crop or area object (e.g. a “ploughing process” could consist of a tractor object and a plough object which are used on a specific date for tillage of a specific area object)
Each of these basic objects may interact with other objects, e.g. each crop object is associated with exactly one area ob- ject, a process object is associated with zero to many device objects etc.
By choosing specific components from a database of predefined object
templates, customisation of those objects and definition of associations between single objects it is possible to represent an in- dividual horticultural company. Figure 1 shows a hardcopy of the graphical user in- terface (GUI) of the information manage- ment software. On the left the object structu- re of the sample company is shown as an ob- ject tree, with each of the main tree branches holding objects of the same type (area, crop, device and process). Note that the real object structure rather equals a complex network of the single objects than the strongly hierar- chic tree structure. A sample of a graphical view of the object structure as a graph is sho- wn on the right of Figure 1.
For the assessment of each specific type of material or energy flow that occurs within the horticultural production system the pro- gram provides one individual interface. Each of these interfaces can be configured to use a specific interface implementation (plugin).
A plugin can be implemented as a hardware driver (e.g. a direct connection to a climate station), a database connection or a mathe- matical model. The input data required by the different plugins is provided by the data model of the horticultural company as de- scribed above: the state of the individual ob- jects in the model, the behaviour of the indi- vidual objects and the structure of the whole model. Figure 2 shows the evapotranspira- tion occurring on a specific area object. In this example the Penman-Monteith model as proposed by the FAO [1] was used as the plugin for acquisition of evapotranspiration data. In a last step these single energy and material flows can be aggregated to a sum- mary referencing the whole company (“gate- to-gate” summary), single area or crop ob- jects. An example of such a flow summary for water is shown in Figure 3.
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Fig. 2: Evapotranspiration for a special area of the exemplary business
Fig. 3: Excerpt of an energy and material flow protocol for one business component
